Some birthdays have more meaning than others and the seventh is one of them, as I realized last weekend.

It was the twins’ birthday party, an intimate gathering of the immediate family. That meant the twins’ mother Erica’s mother Sharon, known as “Nana” to Alex and Sydney, and Carol and me, and, of course, their parents, Ted and Erica.

It wasn’t designed as a grand production (that would come a week later, when classmates and friends would join them). When we felt like it, Ted would fire up the grill, Erica would boil the corn and we would gather at the dining room table.

It’s not to say there wasn’t a level of expectation and excitement. A happy birthday streamer hung between interior columns and the excitement of the morning was still in the air. The twins were up by 5 a.m. and, like Christmas, reveling in the fact that the day had finally arrived. Six was behind them.

It’s a prime number, although I doubt they thought in mathematical terms. But this turning point, more than others we’ve celebrated, was significant to them.

Carol had bags for the girls. Each got a baseball bat with spongy rubber ball and it wasn’t long before a game was in progress, with the hammock tree as first base and the corner stake of the garden as second. Third was somewhere out there, even though it changed, depending how seriously the game was being played.

Sydney took to the game instantly. She has a rudimentary understanding of the rules, and, more than anything, the desire to hit something. She swung at every pitch, finally allowing Carol to provide some instruction, even holding the bat with her and whacking a few balls well beyond the garden.

This is something 7-year-olds do.

Alex wasn’t going to play in the beginning. But then she had her own “green” bat. It was all hers. She was proudly 7 now and she stepped to the plate. She needed some of Carol’s coaching and coaxing. The first hit, barely four feet, brought a triumphant smile and a startled look as she realized she had best race for first.

We expect certain things of 7-year-olds and they know it.

Alex and Sydney are leaving behind first grade. They are no longer fresh arrivals. They’re now part of the system. First graders will look up to them – a new responsibility – and they won’t be at the bottom of the heap any longer.

With the day’s shadows lengthening, Ted fired up the grill.

Everyone made up their plate and moved into the dining room. There was silent chewing on ears of corn and biting into thick burgers sandwiched between melted cheese, lettuce and tomato. Ketchup oozed with each bite.

With a break, I asked Sydney whether she felt any different now that she was 7. It was a provocative question. She expected to feel different and, I suppose, was disappointed there hadn’t been some sort of epiphany between Saturday night and Sunday morning. Alex had the same experience.

“Peppy, I don’t feel any different either,” she announced.

My next question had them baffled.

“What do you think is the best age to be?”

The twins weren’t sure what I meant.

“Well, would it be better to be 16?” I asked.

They thought this over. Neither wanted to be 16, at least not now.

I told them I looked forward to being 16 because at that time I could get my driver’s license. The concept of being a certain age to be eligible for certain things wasn’t foreign, but 16 is a long way away for a 7-year-old.

“What about being eight or ten?” I prompted

No, the girls had made up their minds. Seven was the best. At least, on this day, they were happy being as old or as young as they are.

Alex was the first to blow out the candles topping a pan of uncut brownies. Sydney joined in singing. And then it was her turn. Erica disappeared with the pan and the brownies and reappeared with the candles relit. Sydney basked in the spotlight and the candle glow. She looked thrilled, just as thrilled as when her bat connected with the ball earlier. She blew out the candles with a prolonged breath. We all cheered.

“Seven candles?” I asked. “There should be eight.”

Sydney was incredulous as if I had uttered some blasphemy.

“I’m not eight,” she said emphatically.

“One to grow on,” I explained.

“No, Peppy, I’m seven.”

Maybe she didn’t feel any different when she woke up, but there was no mistaking she felt she had reached a milestone and she wasn’t going to rush getting any older just yet.